How To Store Marijuana Seeds So They Last For Many Years
Incorrect storage can cause any number of issues all of which have the same result: your seeds will no longer germinate.
But if you store them in the proper environment and you keep that environment constant, you can preserve your weed seeds for 5 years or more.
Let’s find out exactly what you need to do to store marijuana seeds the right way and ensure you can still germinate them successfully several years down the road.
How To Store Marijuana Seeds
We often get asked: “Do marijuana seeds go bad?” And the answer is, yes, just like any other type of seed. But if you care for them properly, they can last many years. And that’s exactly what we’ll help you do.
First we’ll cover the ideal condition for seeds, so that you can maximize their shelf life. Then we will cover all of the best containers and locations for actually storing seeds. We’ll also mention a few common ones that are less than ideal.
Ideal Conditions For Storing Weed Seeds
To keep your seeds viable as long as possible, you need to store them in a cool, dark and dry location. The most important thing to avoid are fluctuations in the environment. You want to keep it as steady as possible. Here are the exact conditions you want to provide.
Seeds must be stored in the dark, because light triggers germination. If seeds are exposed to light, even if they do not have any of the other conditions required for germination, the chemical processes for germination are triggered.
This means they begin using up their stored nutrients, which reduces their germination power. When you then try to germinate them later, they may not have sufficient nutrients left and the chances of success are much lower.
Correct humidity levels are vital. If the environment is too humid, weed seeds absorb moisture from the air. This can trigger germination or cause other issues like rotting.
If you are only storing your seeds for a short period of time (no more than a few months) a relative humidity between 20% and 30% is fine. If you are storing them longer, you’ll want to go lower than that. Aim for a humidity level of around 8% to 10%. Even for short time periods, drier is better.
A good way to ensure the seeds stay dry is to include a desiccant in the container in which you are storing the seeds. A common desiccant are those little packets of silica gel that are often included with products that need to stay dry. Include one in the container with the seeds and swap it out every 6 months. You could also use rice kernels in a pinch.
The cooler the better, when it comes to storing cannabis seeds. but only up to a point. You do not want the seeds to freeze, since that can damage them, unless you have the equipment to freeze them rapidly.
The ideal temperature is between 42° and 46° F, which is approximately 6° and 8° C. You can certainly store them in warmer temperatures, but it will reduce the shelf life. If you plan on keeping them for a long time without germinating them, you’ll want to keep them cool.
If a seed gets a steady supply of fresh oxygen, respiration can occur. This may lead to premature germination. To prevent this, store seeds in an airtight container. Inside a vacuum is ideal, but just somewhere that is sealed off is sufficient.
Maintain Fixed Conditions
As mentioned, it is very important to maintain steady environmental conditions. Fluctuations in temperature, humidity, light levels or oxygen levels all reduce the shelf life of your seeds. Furthermore, exposure to the external environment can also allow pests or harmful microbes to enter and damage the seeds.
Best Containers For Storing Marijuana Seeds
People store their seeds in all kinds of different containers. Since they are small, you can put them in just about anything. But many common containers used to store weed seeds are not great. We’ll begin with the best options and end with some that are not recommended.
If you ordered your seeds from a top online seed bank, they probably arrived in sealed packaging. If you haven’t opened it yet, it is best to just leave them sealed in that package.
Whichever type of container you choose, it is best if you can vacuum seal it, or vacuum seal the seeds inside a smaller container within the other one. As mentioned above, keeping oxygen levels low is ideal and the best way to do that, and also ensure minimal environmental fluctuations, is to keep the seeds in a vacuum.
If you plan on storing a lot of seeds, it might be worth investing in a vacuum sealer. Then you can vacuum seal them inside a small container and place that inside a larger one like a glass jar.
Glass jars, like mason jars, are ideal for storing seeds. Their one drawback is that most are not opaque, so you’ll have to keep them in a dark location or cover them with something, so that the seeds remain in the dark.
Ideally, you want to use a glass container with a glass lid. The lid must seal, of course. You want a glass lid, because a lid made from a different material will react differently from the glass to changes in the external environment. This could result in the lid contracting or expanding relative to the glass and weakening the seal.
Plastic Container (Like A Film Canister)
Plastic is not the best material for storing weed seeds, because it has microscopic pores that let in some of the outside environment. They work fine for shorter term storage, but if you are planning on keeping your seeds in storage for a longer period of time, you should avoid plastic.
Plastic Bags (Like Ziplocs)
Plastic bags can work in a pinch, but they are far from ideal. Most are not airtight, which means they can not prevent fluctuations in light, temperature and humidity.
You can use them for short term storage, but you’ll want to find something better for a longer term solution. A vacuum sealed plastic bag that you put inside a glass jar is a great solution, however.
Paper envelopes are great for holding seeds, because they generally keep out light. But they are not good on their own. If you put your seeds in a paper container, you need to place that within a better container, like a mason jar. This is a good way to add some light protection to a transparent glass jar.
Best Places To Store Cannabis Seeds
The following are all good places to store your weed seeds, if you want to ensure they stay viable as long as possible. We’ll begin with the ideal storage space and end with some locations that are less than ideal, but can work in a pinch, for shorter term storage.
Seeds are best stored in a cool, dry, dark location. That basically describes a fridge. With one caveat. You can’t open the door all the time.
That is why it is best if you have a refrigerator specifically dedicated to the storage of seeds. Or at least a second fridge that rarely gets opened.
You regular fridge gets opened constantly throughout the day. Every time you open it, the inside sees fairly large temperature fluctuations. The humidity level changes as well.
If you have no other option, at least put the seeds in the back of the fridge, where they are least affected by changes in temperature from the opening door. If there is a desiccant in the container with the seeds, the changes in moisture won’t affect the seeds either.
If you don’t have a fridge that would work, you could also store your seeds in a cool basement. The main thing to look out for here is that you protect them as much as possible from temperature and humidity fluctuations. You can use some type of insulation the maintain a steady temperature and desiccants to maintain a steady humidity level.
You could also bury your seeds underground. This may seem strange, but if you go down deep enough that changes in air temperature don’t affect the ground temperature, this is actually a great storage location. You’ll definitely want to use desiccants to keep the humidity steady. And, of course, make sure you remember where exactly you buried them.
A regular room in your house can work just fine for storing seeds, too. But it’s more of a short-term solution, since the temperature is likely to be higher than is ideal. You can again use desiccants to keep the relative humidity low.
Common spots are in a closet, a cupboard, or a drawer. Naturally, you want to ensure the seeds are kept in darkness and not disturbed. Stored like this, seeds can still last a fairly long time: even as much as a few years.
Just make sure to protect them from temperature fluctuations. Even if temps are warmer than is ideal, they will be ok, as long as the temperature remains constant.
How Long Can You Store Cannabis Seeds?
If you provide the perfect conditions, marijuana seeds can be stored for up to 5 years and still be viable. If you give them decent conditions and maintain those conditions (i.e. no major fluctuations in the environmental conditions), you can expect the seeds to still be good after a year or two.
Naturally, the longer you store them, the lower the chances of successful germination. Storing them improperly also reduces the rate of germination. So store them well and use them as quickly as you can, in order to ensure the highest possible rate of germination.
Tips For Storing Marijuana Seeds
The following are some general tips that will help you out when storing your marijuana seeds.
It is always a good idea to label your seeds, especially if you are storing a number of different ones. But even if you are only storing a few seeds and they are all the same strain, we still recommend you label them. You may not remember what they even are a year from now. And if there are others in the house, it’s a good way to let them know not to disturb the seeds.
Use Desiccant Correctly
When putting desiccant in the container with the seeds, it is best to keep the two separate. You can create a boundary between the weed seeds and the desiccant by using wool or cotton.
Before you seal your container up tightly, make sure to check it carefully for pests. You do not want a single insect in the jar with your seeds, because it could potentially do serious damage to them. Once you’ve confirmed the container is pest free, seal it up tightly to ensure it stays that way.
Storing Weed Seeds: Final Thoughts
In order to keep your seeds viable as long as possible, you want to make sure you store them in an environment that is cool, dry and dark. You also want to make sure the container you store them in is sealed tight, because the most important factor in making sure your seeds last is a consistent environment. Fluctuations in light, temperature and humidity do serious harm and will likely render your seeds useless.
A glass jar is an ideal container, but your seeds may also already be in a great container. If you bought them online and had the seeds sent in the mail, chances are they are already sealed up tightly. Unless you need to open the container with the seeds, you can just leave them in there.
The bottom line is you paid a lot of money to buy your seeds. Make sure you store them properly, so you don’t end up ruining them and losing the investment you made in them.
How to Store Marijuana Seeds Properly
T here’s a lot of reasons to store cannabis seeds rather than just planting them in soil and letting them do their work. Sometimes you have some seeds leftover from your new favorite strain and don’t have the space available where you live to plant it. Sometimes you’re buying seeds for later use once you’ve got the time and energy for your planting project. Sometimes you’re just stocking up for an uncertain future.
Whatever the reason, you need to be sure those cannabis seeds stay viable in the long term. Properly stored seeds can last for up to five years and still remain viable, and some strains have been reported sprouting at ten years or more. However, proper storage is not as easy as it seems, since seeds are looking for any excuse to start sprouting and there are a number of factors that tell the seeds that the time is right to stretch out their roots and branches. Store your seeds in the wrong conditions and they might end up dead, rotting, or diseased by the time you’re ready to introduce them to the soil.
Fundamentals of Marijuana Seed Storage
First, let’s go over the five main factors to consider when it comes to storing your cannabis seeds, especially for the long term.
When it comes to preserving your seeds for future planting, temperature is the main consideration. In nature, heat is what tells the seed that the winter’s over, which means that it’s time to break open and start sending roots down and shoots up. If your seed’s not in the soil, this means that the plant matter inside the seed will begin to germinate. The shell will crack open, letting the plant matter out and moisture, bacteria, and pests in. Without soil to thrive in, the seed will begin to rot.
41℉ (5 ℃) is the absolute warmest you want your long-term storage spot to be, with the sweet spot being somewhere around 38 ℉.
It’s very important that this temperature remains stable for the long term. If you are refrigerating your seeds, your best bet is to place them in a separate unit or a spot near the back. Every time that you open your fridge the temperature fluctuates, which can harm the seeds over time. While it’s up for debate whether freezing seeds is an effective method for long term storage, we don’t recommend it unless you know exactly how to cure and prepare your seeds. Otherwise, the frozen water in the seed’s cells can expand, destroying the cell wall and killing the seed.
Humidity is another enemy in your battle for long-term storage because any hint of moisture is another clue to the seed that it’s time to stretch its leafy arms and legs. If the seed shell breaches before it’s in the soil, rot can set in.
However, you don’t want your seed too dry either. A humidity level of about 5% is the maximum that you want to allow in order to keep the waxy, protective layer surrounding the seed intact without triggering the seed to split open.
Besides being dark, you want to expose your seeds to as little oxygen and carbon dioxide as possible. These gases are what growing plants breathe, as well as the pests that consume them. If you’re refrigerating your seeds, make your container as airtight as possible. If you have some vacuum-sealed plastic on hand, even better.
Much like heat and humidity, light tells that seed to wake up because it’s time to spring forth. Even if it’s a halogen bulb inside your refrigerator and not the sun itself, the seed’s natural optimism can still start the flowering process.
Light exposure over time can also damage the surface of the seed, which in turn will damage what’s stored underneath. The solution, much like storing cannabis flower and other products, is to keep your seeds in a dark or opaque container. Without exposure to light, they’ll keep dozing long term.
Some cannabis strains (and some specific batches of those strains) naturally produce seeds that are hardier and longer-lasting than others. This plays a role in how long you can expect your seeds to remain viable, so be sure to do some research beforehand.
Storage Methods for Cannabis Seeds
Now that we’ve covered how temperature, humidity, light, air, and genetics work against you when it comes to seed storage, let’s cover the best cannabis seed storage methods.
If you’re storing your seeds for the short term (a couple of weeks or months), a standard mailing envelope or a tan coin envelope will do in a pinch. If the envelope paper is thick enough, it will protect the seeds from the most harmful ambient light. If the envelope is stored in a cool, dry, dark, and temperature-stable spot like the back of a closet or a drawer, the seeds should also stay dormant in the short term. Plus, an envelope makes it easy to Sharpie the name of the strain, the date of storage, and any other important notes you have. If you want to be extra safe about it, throw some grains of rice or a desiccant pack in there to regulate the humidity.
Of course, this method is only as good at the stability of your home’s climate. If you live in a humid area prone to frequent storms or weather fluctuations like Florida, envelopes will only get you so far without ruining your seeds.
Unlike a mailing envelope, glass jars are airtight which makes them much more suitable for long-term cannabis seed storage. Because many types of plastic can let small amounts of water in overtime, it’s highly recommended that you use glass with rubber stoppers. When storing seeds long term, you should also throw in a desiccant pack to keep the humidity stable.
Be sure to separate the pack from the seeds with a couple cotton balls or a paper towel. This will help absorb excess moisture at the start as well. If you have a method to vacuum seal the jar even better. Wrap the jar in something opaque and you’re all set. Seeds stored at a stable room temperature can last for over a year. Refrigerated they can last a couple years.
If you’re looking to store your seeds long term, vacuum sealing your seeds in thick Mylar bags can keep your seeds viable for up to half a decade. Since the bags are designed for long term storage, they’ll work well for your seeds as long as you make sure they were stored at the right humidity (a desiccant pack helps with this) and away from the light. This is one of the best options if you’re refrigerating your seeds.
Seeds of Wisdom
In conclusion, cannabis seeds can be stored for the long haul and stay viable as long as they’re kept away from heat, light, moisture, and air. The more care you put into your storage method, the longer your seeds will last. However, when it comes to planting seeds with the most chance of success, sooner is always better.
What are your best methods for storing seeds? Share in the comments below!
Seed Storage 101: How to Store Cannabis Seeds
Not all of the seeds that you purchase always end up in the ground for planting the season that you purchase them, which means the left overs require storage. However, if they aren’t stored correctly, you risk losing that seed to environmental factors that could affect your crop – or maybe it won’t grow at all. This article is about how to correctly store your seeds until next season.
So you’ve just received your latest shipment of 25 seeds from your favourite seed bank—and you only plan to plant 5 or 10 of them this season; or you’ve just finished this season’s harvest and you’d like to store the seeds you’ve collected for your next crop … Proper storage of cannabis seeds is an essential aspect of ensuring the viability of future marijuana crops.
There are two types of seed categories:
- Orthodox Seeds – these seeds enter a dormant stage and will survive drying;
- Recalcitrant or Unorthodox Seeds – seeds that will not survive drying and are susceptible to desiccation injury.
Cannabis seeds are the orthodox type, or desiccation-tolerant, and can be prepared for long-term storage without risking instability.
Key factors to consider when storing seeds are environment and container. Environment is important because moisture levels, temperature, and light exposure all play a role in the stability of your seeds, along with oxygen and ethylene concentrations. The container you choose for storage plays an important role in that the proper environment will be maintained if you use the proper receptacle. Hand-in-hand, these factors help ensure the viability of your seeds for either long- or short-term storage periods.
Environmental factors that affect the viability of cannabis seed are:
- Moisture – reducing moisture exposure ensures seeds won’t prematurely germinate or become mouldy.
- Temperature – fluctuations in temperature can lower a seed’s longevity significantly.
- Light exposure – light is required for germination; over-exposure may cause seeds to come out of their dormant stage and encourage tissues to mutate.
- Ethylene concentration – ethylene is an important natural plant hormone; seeds begin to produce ethylene immediately after exposure to water or moisture (another reason low moisture conditions are necessary during storage).
- Oxygen concentration – lowering oxygen exposure will reduce or prevent seed respiration during storage, thus deterring premature germination.
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It is important to dry your seeds gradually and thoroughly before storing them—although not to 0% moisture, as this can result in the death of a seed. During ripening and drying, cannabis seeds will prepare for dormancy by slowing or stopping most physiological processes. Ideal moisture percentage is 2-3% and can be achieved by placing a desiccant in the storage container with your seeds. (A desiccant is a hygroscopic substance that induces or sustains a state of dryness in its vicinity (draws out water). Commonly found pre-packaged desiccants are solids that adsorb water, e.g., silica gel packs. These can be found at Wal-Mart, Uline.com, or your local florist!). Rice is also known to be an effective desiccant, but should be replaced periodically. The use of a desiccant when drying seeds greatly improves their stability.
Keep cool, keep dark, and keep dry! Maintaining a constant environment with little or no fluctuation is vital to ensure the stability your stored seeds.
The jury is still out on the best location for optimum storage results—each having pros and cons; here are the most common recommendations: